Various compression devices are known for applying compressive pressure to a patient's limb. These types of devices are used to assist mainly in the prevention of deep vein thrombosis (DVT), vascular disorders and the reduction of oedema. U.S. Patent Application No. 2004/0111 048 (Jensen, et al.) and U.S. Pat. No. 6,786,879 (KCI Licensing Inc.) disclose such devices.
Compression therapy is used in the treatment of venous leg ulcers. The treatment relies on the compression achieving a reduction in oedema and improved return of blood via the venous system. This, in turn, reduces the residence time for blood supplied to the lower limb and the severity of ischaemic episodes within the limb that can result in tissue breakdown.
Compression of the limb in the treatment of venous leg ulcers is most usually achieved by the use of elastic bandages. Elastic bandages have the advantages that the patient can be mobile; can be treated at home; and that once applied by a health care professional, any removal or interference may be possible to detect. Elastic bandages do, however, have many disadvantages: they can work loose; the pressure generated by the bandage on the limb is not measured and depends on the level of skill of the health care professional applying the bandage; the level of compression is also affected by the circumference of the limb; the bandage cannot be removed and reapplied by the patient, for instance, for bathing; and many patients find them unsightly, uncomfortable, hot or painful.
Compression of the limb in the treatment of venous leg ulcers can also be achieved by the use of compression stockings, although they are most often used in the prevention of leg ulcers, for instance, in the prevention of recurrence after an active leg ulcer has healed. Compression stockings have many of the advantages of elastic bandages: they can be used at home and the patient can be mobile. They, however, have some disadvantages; they are difficult to apply as the narrow ankle part has to be pulled over the heel; compliance with treatment is difficult to monitor as the patient may be able to remove and replace the stocking themselves; and patients can find them uncomfortable.
Compression of the limb can also be achieved by a pneumatic compression device. As venous leg ulcers are most usually treated at home or in the community and the known compression devices are large, heavy and require professional supervision, their adoption for such treatment has not been widespread. The known devices, used previously, apply pressure to the limb through a thick cuff or cuffs which affect patient mobility and are aesthetically unacceptable to many patients. The pump which produces the compression is large and heavy and can supply fluid to the cuffs through many pipes. These characteristics make the known devices unsuitable for domestic use.